Amphoteric surfactants have been used for many applications including personal care, mining, improved oil recovery (IOR), oil field drilling, fracturing, acidizing, foaming, and agricultural formulations, etc. because of their unique properties such as electrolyte tolerance, hard water tolerance, mildness and low irritation, foaming, wetting, interfacial tension reduction, viscoelasticity, and thermal stability. U.S. Pat. No. 7,373,977 discloses the use of certain amidopropyl dimethyl betaines and alkyl dimethyl betaines as viscoelastic surfactants for oil well stimulations. U.S. Pat. No. 7,556,098 discloses the use of certain unsaturated amidopropyl dimethyl betaine, alkyldimethyl betaines, amidopropyl dimethyl sultaines, and alkyl dimethyl sultaines to lower interfacial tension (IFT) to ultralow values for the recovery of residual oil. However, for oil field applications, one of the shortcomings of these products is their high adsorption to solid surfaces. The high adsorption of the amphoteric surfactants onto the formation rock prevents the surfactant from propagating through the reservoir and the oil recovery is limited. It would be very valuable if an amphoteric surfactant or surfactants could be developed having all the desired properties of existing amphoteric surfactants with low adsorption onto the solid phase.
U.S. Pat. No. 5,371,250 describes a method of preparing pure aqueous betaines by reacting tertiary amines with an α-monohalocarboxylic acid, and an alkali metal hydroxide in the presence of water to make the betaine. The aqueous betaine solution is then treated with a sulfonating agent to convert the alpha-monohalocarboxylic acid into the corresponding sulfocarboxylic acid to make the highly pure aqueous betaine solution of the formula.
A recent article, Dynamic Interfacial Tension Behavior of Alkyl Amino Sulfonate in Crude Oil-Brine System, Tenside Surf. Det. 50 (2013) 5 pages 369-375 describes the interfacial tension behavior of alkyl amino sulfonate. Although the IFT of these surfactants may achieve ultra low values with certain oil and brines, the challenges of the surfactants are the adsorption rate onto the rock. In addition these surfactants are anionic in nature and it is well known in the industry that anionic surfactants are subjected to limited compatibility in brines containing divalent cations. It would be very valuable if a surfactant can provide low adsorption properties onto the rock, compatibility with the various brine composition, low IFT between the injection fluid and oil, stability at higher temperature, and effectively recovery the residual oil.